re: Advice on handling a hypochondriac?

Not a bullshite story here. I knew a co-worker, real name Don R., who often left his job to run by the ER or doc in the box because someone in the office mentioned they might have sore throat or some other malady and he would immediately think he may have it too. It could be someone complained to him about their back hurting pretty badly and boom, he was out the door to get his aching back checked out.
I knew his supervisor well and we would talk about this strange deal. It wasn’t that he wanted to skip out of work because he was a very valuable and high performing employee and loved his job. It was this fear he had that, merely by suggestion, would trigger him to think he might have whatever health issue someone complained about.